Mobile communication devices may include a variety of components including circuit boards, integrated circuit (IC) devices and/or System-on-Chip (SoC) devices. The components may include processing devices, user interface components, storage and other peripheral components that communicate through a shared data communication bus, such as a multi-drop serial bus or a parallel bus. General-purpose serial interfaces are known in the industry, including the Inter-Integrated Circuit (I2C or I2C) serial bus and its derivatives and alternatives. Certain serial interface standards and protocols are defined by the Mobile Industry Processor Interface (MIPI) Alliance, including the I3C, system power management interface (SPMI), and the Radio Frequency Front-End (RFFE) interface standards and protocols.
The I3C serial bus is a serial bus that has an intended use in connecting sensors and other peripherals to a processor. In some implementations, multiple bus masters are coupled to the serial bus such that two or more devices can serve as bus master for different messages transmitted on the serial bus. RFFE standards and protocols define a communication interface that may be used for controlling various radio frequency (RF) front-end devices, including power amplifier (PA), low-noise amplifiers (LNAs), antenna tuners, filters, sensors, power management devices, switches, etc. These devices may be collocated in a single IC device or provided in multiple IC devices. In a mobile communications device, multiple antennas and radio transceivers may support multiple concurrent RF links. SPMI standards and protocols define a hardware interface that may be implemented between baseband/application processors and peripheral components. In some implementations, SPMI is implemented to support power management operations within a device.
In many instances, a multi-drop serial interface may be provided to support high-priority, low-latency communication between an application processor and certain peripherals, and other lower-priority communication. Latency can be adversely affected when multiple devices coupled to the serial bus are concurrently active. Degraded latencies can lead to an increase in dropped packets, session timeouts and retransmissions on the serial bus. As mobile communication devices continue to include a greater level of functionality, improved serial communication techniques are needed to improve latencies and/or handling of priority traffic on a serial bus that couples peripherals and application processors.